Reliability of Field-Based Fitness Tests in Adults: A Systematic Review

Background Physical fitness is a powerful predictor of morbidity and mortality, and is therefore a useful indicator for public health monitoring. To assess physical fitness, field-based tests are time-efficient, inexpensive, have minimal equipment requirements, and can be easily administered to a large number of individuals. Objective The objective of this systematic review was to examine the reliability of existing field-based fitness tests used in adults aged 19-64 years. Methods A systematic search of two electronic databases (MEDLINE and Web of Science) was conducted from inception to 8 June 2021 by two independent researchers. Each study was classified as high, low, or very low quality according to the description of the participants, the time interval between measurements, the description of the results, and the appropriateness of statistics. Three levels of evidence (strong, moderate, and limited) were established according to the number of studies and the consistency of their findings. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO reference number, CRD42019118480). Results Of 17,010 records identified, 129 original studies examining the reliability of field-based fitness tests in adults were considered eligible. The reliability was assessed of tests of cardiorespiratory fitness (33 studies: 30 of high quality), musculoskeletal fitness (92 studies: 78 of high quality), and motor fitness (22 studies, all of high quality). There was strong evidence indicating: (i) the high reliability of the cardiorespiratory fitness tests: 20-m shuttle run, 6-min step, and 6-min walk; (ii) the high reliability of the musculoskeletal fitness tests: handgrip strength, back-leg strength, Sorensen, trunk flexion sustained, 5-reps sit-to-stand, sit-and-reach and toe-touch, and moderate reliability bilateral side bridge and prone bridge tests; and (iii) the moderate reliability and low reliability, respectively, of the motor fitness tests T test and single-leg stand. We found moderate evidence indicating the moderate or high reliability of the following tests: Chester, sit-up, partial curl-up, flexion-rotation trunk, timed stair ascent, pull-up, bent-arm hang, standing broad jump, hop sequence, trunk lift, timed-up-and-go, and hexagon agility. Evidence for the reliability of balance and gait speed tests was inconclusive. Other field-based fitness tests demonstrated limited evidence, mainly due to there being only few studies. Conclusions This review provides an evidence-based proposal of the more reliable field-based fitness tests for adults aged 19-64 years. Our findings identified a need for more high-quality studies designed to assess the reliability of field-based tests of lower and upper body explosive and endurance muscular strength, and motor fitness (i.e., balance and gait speed tests) in adults.